METASTABLE TETRAGONAL CeO2-ZrO2 SOLID SOLUTION

En refroidissant, en conditions hors équilibre, les solutions solides de structure fluorine zircone-oxyde de cérium, on a obtenu une nouvelle phase, riche en CeO2, de structure tétragonale au lieu de la phase cubique, stable à haute température.When ceria-zirconia solid solutions with fluorite type of structure undergo a non-equilibrium cooling treatment, a new metastable, CeO2 rich phase, of tetragonal symmetry is obtained instead of the high temperature cubic phase

Mechanical properties of flo-deflocculated and milled powders in the Al2O3/ZrO2(CeO2) system

Samples of alumina, zirconia and their mixtures were prepared using powders produced by two different processes. The first process only involved the flo-deflocculation of diluted suspensions whereas the second required two steps, first flo-deflocculation and then ball milling of the slurries. Materials comprising a matrix containing a relatively small quantity of the dispersed phase (20 vol% and 80 vol% ZrO2) show better properties when they are produced from flo-deflocculated powders. When samples contain a large quantity of the dispersed phase, milling after flo-deflocculation is beneficial because it provides better homogeneity, which provides greater density and strength although toughness is not significantly improved